St. Robert Bellarmine on Human Happiness and the Commandments

"Truly then the recompense is great for those who keep your commandments. That first and greatest commandment helps the man who obeys, not the God who commands. In addition, the other commandments of God perfect the man who obeys them. They provide him with what he needs. They instruct and enlighten him and make him good and blessed. If you are wise, then, know that you have been created for the glory of God and your own eternal salvation. This is your goal; this is the center of your life; this is the treasure of your heart. If you reach this goal, you will find happiness. If you fail to reach it, you will find misery.

"May you consider truly good whatever leads to your goal and truly evil whatever makes you fall away from it. Prosperity and adversity, wealth and poverty, health and sickness, honors and humiliations, life and death, in the mind of the wise man, are not to be sought for their own sake, nor avoided for their own sake. But if they contribute to the glory of God and your eternal happiness, then they are good and should be sought. If they detract from this [goal], they are evil and must be avoided."

Source: Liturgy of the Hours (volume 4; pp. 1411-1413), Office of Readings for St. Robert Bellarmine, Sept. 17, 1412-1413; Grad. 1 [On the Ascent of the Mind to God]: Opera omnia 6, edit. 1862, 214.